Nanosilver/silver nanoparticles (AgNPs) are the top ranking material used in nanotechnology- enabled consumer products. Due to unique antibacterial properties AgNPs are increasingly being used in health and personal care products, clothing and sporting goods, cosmetics and the food sector. The use of AgNPs in food contact materials, dental care products and dietary supplements, the possible use as antibiotic replacement in animal feed and environmental contamination with their disposal products indicates that oral intake is a major route of exposure to AgNPs in the general population. Thus, it is important to understand whether AgNPs are genotoxic and/or carcinogenic when ingested orally. We recently reported that oral exposure of mice to polyvinylpyrrolidone coated-AgNPs induces DNA deletions, strand breaks and oxidative lesions and downregulates base excision repair genes. Different coating agents are used to prevent aggregation and dissolution of AgNPs. We hypothesized that nanoparticle coatings may influence genotoxicity of ingested AgNPs. The proposed studies linking physiochemical properties to biological effects of nanomaterials seek to establish how the presence or absence of different surface coatings modulate oral bioavailability, tissue accumulation and genotoxicity of AgNPs. 2.